148 Tlie RocTcy Mountain Locust. 



vals, it is next to impossible to do this in practice during 

 the winter season as effectually as it was done in the 

 experiments ; and the only case in which water can be 

 profitably used is where the land can be flooded for a few 

 days just at the period when the bulk of the eggs are 

 hatching. 



Experiments to test the Effects of Exposure to 

 the Free Air. — The eggs in the following series were 

 obtained at Manhattan, Kansas, in November, and all 

 under similar conditions. 



Experiment 26. — A large number of egg-masses were thoroughly 

 broken up and tlie single eggs scattered over the surface of the 

 ground out-doors early in December. By the 23d of February all 

 had perished, and most of them had collapsed and shriveled. 



Experiment 27. — A large number of pods were partly broken up 

 and exposed as in Expt. 26. On the 10th of March the outer eggs 

 were mostly dead and shrunken, but a few of the protected ones 

 were yet plump, the embryon well advanced and apparently sound. 

 Placed in earth they subsequently hatched. 



Experiment 28. — A large number of unbroken pods were exposed 

 under similar conditions as in the preceding Expts. By March 

 10th fully three-fourths of the eggs had perished, and by April 1st 

 all had perished. 



Experiment 29. — Fifty egg-masses were kept in-doors in an open- 

 mouthed bottle in perfectly loose and dry earth from November 

 6th. Fully eight per cent, of the eggs had hatched by December 

 28th, when hatching ceased, and a subsequent examination showed 

 the rest to have shrunken and perished. 



It is very evident from the above experiments that we 

 can do much more to destroy the eggs by bringing into 

 requisition the universally utilizable air, than we can by 

 the use of water. The breaking up of the mass and 

 exposure of the individual eggs to the desiccating effects 

 of the atmosphere, effectually destroys them; and when to 



